House electric



Aug.4 26 1924.

' Re, 15,898' B. O. AUSTIN sysrnu oF connor. v

Original Filed Oct. 6; 1919 4| Grpund/ I 5 l l in 6a 7464 '5a I 29 Rl-n 3 I,

l 79 78 w+ l l al @0 L52 G VWTNESSES: INVENTGR Bascum o. Ausf@ Nom@ t may concern: i

't Qwnthat 1, BAioUisLv AUSTIN,

9 uw;.nlef1-.siteresido ai the 'county @1 Alles,v env ofr Pennsylvanla,` have .mie'nted and Vuse ful` In: rovements in lobontnol; and do ereby` declare `xng .=p be @#1111, clear, andxat tion. ,of the .in ention, suclrrasl will othersskfuled 1n the an@ which it make and use the same. vpn'on ning elatea to systems ,of control gkctricrpinchinesy and it ,hns

n totheQautomati'c control aymotorsand'the like.

- i `ly intention i Prende t ing. paratus in a system .gxthe aibqyeidicatharccter whereby aimalircg or ld-controlled eceleration of pi met icurlent o1; neet-current phpgplyand reliably e'ected.

' .chisme it Vis www mmtiQ/qsmmth Operation,v .0f oneens ofa sequence switch by .pilot motqrgt he enerh y is` dependent upon the slytwfthe M tunesthe pilot motor is operated Moggi glpachine, while, asvsoon ;ttlie, 'ninlidnoton ircutAi is c1osed, the

t lmotor `1sV @automatically inaugut iroqnthe Ifo owing detailed descriptakonygnoonjunction with vthe aocomf.

mgjldtawing wherein Y ,..1,` is a simplified diagrammatic moi-a. system ot control embodying the mrqiplesfpithtpment invention;

n uw leielfdsgflmmatcwew of. .the main crcm'tg gi;1inother;anotorsystem to -mhehmr' 'mientlwmy be applwd; L fg .vk-3.51am dit lnmatic vew of the ary ,pn contro gciifcuits organized-.in 5 0 mdgnoqfyvith m ,invention for governing thl'ewainimot th z jFgmyis @sequence chartgot well-known ating geirlggnltjonnd fcontrolled, V action vof ofv k linventionwillhecoine 'at aren-shown in Fig. 2;-

ffhfi'i'ivfif- A Q v i w i @UNITED STATES., NPATEIJT UFFICI-1..

ih," f 'v ."4 1--^ el t y l Aarem, or wmxmsnnne, PENNSYLVANIA; 'AssIGNon Townsmejoosnfleme'rnic' a lMANUFAcrrUnnste ciolinlPAmr,r A CORPORATION or PENNs'zIr 1 u svs'rmll or comuni..

`29, im, Serial Ko. 328,847, med October 6, y1911.9. tot reunie mea Apriit, 1924. serieu` No. 7o4,2s9. t

form serving to indicate the order of o '4 rdton of the various switches ,that ere s own in Fi?. 2. 'l Q. Re erring to Fig. 1 ofthe drawing; ythe system here shown is of the alternatingcurrent s inglehase` typecomprising su' plycircuitcon uctorsTroll'ey and Ground.;

'a main motor fhavinga cominutatorltype armature 1 an e citing ,or magnetzi field WindiniFl fa. neutrglizing o i'f ensating e d winding C1.;^a, pilot niotor 1 'y or governing the operatmn ofthe main motor and which is-.itself controlled in' rt by a. main-circuit line switch LS'; an ,an

i inductive -device 2 that is connected incir- "cuit with the pilot myotorilfor a. purpose tobesetforth.; .v The pilot motor .1 comprises a commutator-t armature 5 and an exciting fxeld win i a Inova le contact dskor plate 7 for Oompleting the circuit of the main driving mofor connect 4the min eld winding" TS1 andthe field winding 6 of-the pilot motor iii parallel relation under main-motor operconditions. y, if

Initially, that isybefore the main inotor is started into o eration,` a. circuit ,ispaniletedfrom the rolley through switch 9,

6. The line switch LS comprises tor and an' interlock or auxiliary switch 8 i inductive device 2 the ,tirmature 5 andthe field winding 6 of the" i1o t inotor '1 A to Ground. lIn this way, t e pilot motor `is initially connected ltn run as astraight serios motor to aetueite-a drum controlleror the like (not shown) through the vagency of 'a suitable shaft `11, for example, for vthejpurpose of., oyerning the connections'ofthe .main dr1ving' motor or for returning the .drumcontroller to its off -position 'Howeven upon the closure ,of the line switch L S, keither by the drum controller in question orbyz other means, a main circuit is establish d from the Trolley thro h the contact mem e127 of the line switch, eld Winding (l1-armature A1 and field winding F1 of the ln'ain motor to Ground. `The closure of the -switch LS completes a. circnit'iroin :Ground through the main eld winding Fl,

-auxiliary switch. or interlock '8 of the linie switch LS; conductor 10 and Held-winding' 6 of the pilot motor to Ground. Consequently, the 'current traversing.the-plotrnotor Whit ddwi f thei field winding 6 and, therefore, the s eed of the ilot motor is dependent npoirpt e 10ml of main motor. Since the opetiug speed ofthe pilot motor determines the rate ofjacceleration of the ma'm motor, it follows that such acceleration will "be :effectedr in a desirably smooth and radual manner without requiring the use o current rel'dys or the' like to intermittently interrupt the control I d l 4 n, A o For direct-current service, the Inductive degice 2 is not necessary, but should prefer- :y-oo ompfoyoo 'ro alternating-@Hoot Syos' of the 'type shown in Fig. 1 in odr to 1obtain more reliable o ejrat'on. In additliofnto thotomatlo oo ol o tiro lot motofi, through; tho modulo),V of um; oad our;

font traversing the mai eld winding F1, a

getij the pilot motor by e' any f 'sin power-factor of the main motor, ouali-goa will offoot oforfhor' Slown r pilot ,ni'oto5 under heavyy foo:

conditions of the' main `driving motor. It om,y to unooocooo that my sivo-outa applied to iduc ion motors by' connecting the excitingr eld further regulating notion wirf; be im "ood i v Winding of the lot motor, nder operating conditions of t e system, crosse resistor controlL of xcrl'fli"iductorl in thelmaitlpr secondary cirs of the induction motor. Referring that, is illustated inFig. 2,@ plurality of iA l1 .lotoi-`s,`rmL ectively hatfi aina tls 3 and A4 a rfield vtifidill S F3 and F4, are adapted for series-para el to inA conunotion with an 'ac'celeratii evsst'or 12 byimeas of a plurality swi es LS1 and L82 for governing" the' liiretconuctiol's, R1 and R2 for short-circitig the VE errin to the ovrni'l s' 1'steril shown ,Matino i g y govern Se Velflce switch'llforfeflectig d y t e ractuatilig 'coils for the vlariotsV switches that are i1 Y undef ,pr'odooormiooc ofofotiogfeoodiaooo, together with a plural tyfofihterlocks or auxiliary-circuit members, of -the familiar t that is shown'l'i connection with the sw tch L52 in Fig. 2', and a master controller MC for primarily directing derived from a controlresisto 16" tot e' Vacircuits. l

Assuming that itis desiredto effect acleeleration of the motors illustrated in' Fig.

2 an auxilia switch 23, which' is preferablylo ucrateri y foot, is concurrently moved .tovar y tion. Under such conditions theleft intoA acircuit-closirl osiva' circuit is tobliohod from tho Trolley droogt condoo- T 20,' control fingers 21 and 22, which are '43 in" the contro resist *Si :main motors are coffoooifod iii series' Hon to the direct-current' Y' pilotI `mower io odo'ptod' tok torse, control fingersr aal and Winding described load ootrol'of Ehepilot' lti '1 bridged by the foot-controlled switch 23 1iin its eratqe sitiom actor'iand te 13a miao? lo, tomaal.

The preferred form of mechanical interlocking 4beulveen the foot-controlled switch 23 andthemaster controller M6,- whereby false operation is prevented,is set forth and clilirnd in a copending application of Louis M. Aspinwall and Harry R. Meyer, Serial *No 335,492; fired Nov. 3;' fois, ao assigned tof the Westinghouse Electricl & Manufacturing Company. v

VAs, soon -astlie control resistor 16 is eher*-v gized, ya. crcl'lits established from atappo; io he o'ootlr'ol rooffoio; solo? oouf `or 2,- o"io1i" in ,famous oon of ola sog switch gsi, I G-out' and MS2-o to' a secmid tap-point the lille ksvitkfi isi-clos", as ild n Step d of the sequence' chart, Fig; 4 llplao o mio ofi-ooit (Fig. 2y' fro-fs he for. ley throog'ffooodootoi 44, nouoflpoise 4a, conductor 46', switch L Lxcdctor 47, jonction-point 48, sold wiffdr T3, afiliat'r 'the entire acceleratirigisdr' 112 armature A4,"junctio'i-'poi t $2? ridfiel-'d winding Fs fo Ground. i lo this tho ,with the coolers-fing resistor 12 coloso eso so ly circuit; l

@moin oifrou'if -oonffootioos are Hoeof in'y prsent invention, but d set -fbm 85d cl'ain'ied" in a copdifg ic'tn i WH. coudes,- Sool 1 Ao; $9,842, f t; o, wie, ma stguoa to elle Westin house' Elootffopa aoufioggm' Goal master controller :93 5 sto' Vits opo'roefto omo of owe spf mog to series connect ofof thfii's aad-ooratioo fhoroofioA the fom. ce; uoo f tampon a oifooit is' om listos-pom so tur-ooge condoom so fialeaoa-poioe 27, ooodoo'fof 2s connor mgsfs ze and aogwhioh aio Bridget loV omas-sog meno 31' of thoooqooooo wao is, asadostsldgod by oonfaoe sog-montes of t p mosca: controller. conductor 36, control iin :"87 4uld 88, which are bridged B con tor 40; armature 5 of the pilot motor Lectiductor 41, 'unctioii-pdnt 42 :tijd fiedw@ ing e of t o pilot fflocor to Groane. 'The pilot motor' I 1s thus started i'to o 1";

sequence switch 15 gduflly approaches f' its second aperitivo positift As soon as the ourreirt intlffo mailiold F4 has built up, the previouslycomes into effect by reason of the' fa-tl't conductor 50 connects junction-point 49h@-A tweenV the armature A4 and the field WM- ing F4 with junction-point 42 bet-wem the vno . and field: winding 6 vof the pilot motor. In other words, the field windings F4mnd 6 are-connected in parallel relation, as described in connection with Fig. 1, and `l subsequent operation ofthe pilot motor 1 is dependentI 'upon the load of the main dri gmotors. 2 action .of the 'lot motor may be more fully explained as fldllows: While zero currentobtains inthe main field winding F4, the Yjunction-points 42 and 49 are practically atggltound` potential, since the resistances of 'theidield .windings F4 and 6 are very low. uently, a maximum voltage 1s im- Yw.' acr the pilot-motor armature 5 and a minimum voltage across the field Winding. .l On the other hand, with fullcurrent flowing through the main motors, Ijumition-points 42 and 49 have an appreciable potential by reason of the volt- Aagefdirop across the'main field winding F4; 01-` Ain lother words, the armature `voltage is l: and the field-winding voltage is in the pilot Lnmtor.

finder accelerating' conditions, the armthreand the field lwinding 6 of the pilot are'joimtly and-directly affected .teprodunezanincrease or decrease in the apeedof the sequence switch 15. AvyAlsacienne the sequence switch 15 reaches .iti position "e, another `circuit is established fl-pm a tl. point 55 in the control resistor 13,' conductor 56,` control fingers 57 and 58,` which are bridged b lcontact seg- -mnt 59 of-the master control er, conductors 60 and/66,!actuating coil of the switch R1, emulador `66, control fingers 67 and 29, .mhiichm temtporarily` bridged by'contact c 31 of e sequence switch'l. thence .thnoughconductors 28 and 26 to the tap- Qvrnthe control resistor 16.` Y 'rh-M8001: a's the switch R1 is closed, a holding `circuit is established from the contact beglwtrl 'through control finger 68, con- MP ductor 69 and interlock. Rl-in to the confdlietor- 28, Consequently, the disengagement 1 oiifcontrl nger29 from the contact segmnt Min-position e does not affect the sy.. i Furthermore, the previouslytraced circuit for the ilot motor 5 between `conductors 29and 32 1s bridged by another of "the above-mentioned interlock `)ein and, therefore, the disengagement of lcontrol fingers 29 and 30 from the contact segment 31 does not interrupt vthe pilot- (motor-circuit l f As the sequence switch approaches its next position f, a ynew circuit is completed from theenergized conducto-r 65, through conductor ,70, actuating coil of the switch ill-2, conductor 71 `and control finger 72 to contact `segment 31, whence circuitis mtnlledfto the tap-point in the control resistor 16,. as' previously traced.

t Coneaquently,in positions e and f of the sequence switch, the resistor-12 is shortcircuited in steps to effect smooth acceleration of the motors to full series relation, as represented by `position f of the sequence switch. f'

The pilot motpr 1 is cle-energized just before position f 1s reached by reason of the disengagement of control finger 37 from the Contact se ent 39'. Consequently, the sequence sw1tch 15 automatically stops in its series connecting position f-when the master controller occupies its ition b.

However, by actuatlng the master controller MG toits position c, a new circuit is establishedv :from the contact segment through control finger 73, Iconductor 74, and control finger 75 to contact segment 39 of the rsequence switch. In this way, the pilot motor 1 is again energized to actuate the sequence switch toward its position g. Although the circuit just traced isl inter.- rupted in that position, the initially traced circuit including control lfinger-37 is again established by that time by reason of the peculiar configuration of the contact segment 39 and, therefore, continuous movement of the sequence switch from position f to osition h occurs.

fter the sequence switch leaves position fa new circuit is established from the energized conductor 70, through conductor 77, actuating coil of the line switch L52, conductor 78 and control finger 79, to contact segment 31. The line switch LS2 is thus closed to effect adirect connection between trolley-connected conductor 44 and an intermediate point`84 in the acceleratinggresister 12. The switch LS1 lthereupon drops out by reason of the exclusion of the interlock LS2-out from the circuit of its actuating coil As the sequence switch approaches position g, control finger 67 becomes disengaged from the contact segment 31 to effect the opening of switch Rland, subsequently, contact segment 31 engages control finger 80, whence a `new circuit vis continued through conductor 81, interlock LS1-out, actuating coil of the switch G, conductor 82", interlock R2-in and conductor 83 to the tap-point 43 in the control resistor 16. l

The two sections of the accelerating resistor 12 are thus connectedv in parallel rela-- tion since the switch R2 remains closed, and the main circuits (Fig. 2) may be traced as follows: from the Trolley through conductor 44, junction-point 45, switch LS2, junction-point 84, the parallel-connected sections of the resistor 12 and switch R2, where the circuit divides, one branch including armature A3, field winding F3, junction-point 48 and switch G to Ground, while the other branch includes armature A4, junction-point 49 and field winding F4' to Ground.

Energization of the pilot motor 1 and,

therefore, movement of the sequence switch continues until position k is reached. whcreu the control finger 37 again becomes 'sengaged from contact segment 39 to de-energize the pilot motor and effect Stoppa e of the sequence switch in the full paralle position h. f

Ils-this position, control finger 67 again engages contact segment 31, whereby the Switch R1 is closed to short-circuit both sections of the accelerating resistor 12 and thus connect the motors inK full parallel relation.

To return the sequence switch 15 toits illustrated initial position d, it is not necessary to reverse the connections of the pilot motor 1, since the sequence switch 15 is ladapted to operate always in'` one direction or, in other words, movement of the switch beyond position It serves to turn the switch, if of the erred drum type, Athrough, a given ang until initial position d is occupied. Such movement of the sequence Switch is yobtained as follows: The master controller MC is returned to its oil position, when it isv desired to stop the car, whereupon theV switch R1 opens by reason of the de-energization of its actuating coil, while the line switch LS1 again closes by reason of the 1re-insertion of .interlocks G- out and LS2`out in the circuit of its `actuating. coil.A By moving the master controller1 to its position b or any other operative positionsr when it is desired to again accelerate thenaotors, the conductor 66 is energdzedY and a circuit is completed therefrom throo 'onction-point 61, conductor 62, intel-locks and LS1-in, conductor 63, control 64 and-contact segment 39 of the sequence switch 15in its position k. Such energizwtion obtains until the: sequence switch 15 has been rotated in the constant direction as Afai: as the position d, where the pilot motor circuit just traced is interrupted?,` but the sequence switch continues to move because of the rta-establishment of the control circuits already described, in connection with v initial position d.

Furthermore., the proper action automatically occurs even though the sequence switch occupies some operative positionI other than h, w en it is desired to stop the vehicle. In suelta case, the'master controller is simply returned to its of position and is Subsc; quentlfy actuated to the operative poVL sition, vwhereupon the sequenceI switchk runs through the remaining operative positions and as far as initial position d, as previ ouoly described. No' switches are actuated duringthis operation for the reason that control lingers 29l and 30 of the sequence switch do not engage the Contact segment 31 in any position except d, so that the actuating coils of switches R1, R2', L82 and G cannot be energized through those control fingers. Moreover, the control lingers 29,

' effecting and 68 are not bridged by either of the interlocks Rl-in and LS2in, since the corresponding switches both occupy open or out` positions.y a

Consequently, the pilot motor 1 operates as a straight series motor to quickly turn the` drum 15 to its initial position d, irrespective of what other position the drum occupies when the master controller is actuated to an operative position to begin another movement of the vehicle.

I do not wish to be restricted to the specific circuit connections or arrangement of parts herein set forth, as various modifications thereo may be made without departing from the spirit and scope of my invention. I desire, therefore, that only sach limitations shall be imposed upon my invention as are indicated in the appended claims claim as my invention:

1. In a system of control, the combination with a main dynamelectric machine, of a controlling device therefor, an auxiliary dynamo-e ectric rnachime'forl acuating said device, and means for causing smid auxiliary machine to'operate in accordance with the main motor loadV and own load under different operating conditions of the'system.

2. Ina system of control, the combinationI with a main dynamo-electric machine, of a controlling device therefor, a` switch for eliecting certain main-machine connections, an auxiliary dynamo-elcctric-maehime for actuating said device, and means gh governed yby said switch for lati the operation of said auxiliary mgilne. ng

3. In a systcnr of control, the combination with a main dynamo-electric machine, of ai controlling device therefor, switch for ewecting `certain main-machine' connections, an auxiliary dynamo-electric machine for actuating said device, andr means for energizing said auxiliary machine as a series motory unless said switch occupies 'a predetermined position.`

4. In a system of control', the. combination with a, main dynamelectric machine, of a controlling` deviceA therefor, a `switch for certain main-machine connections, an auxiliary dynamo-electric machine `ior actuating said device, and means responsive to the closurev of said switch for rendering the energization of said auxiliary machine dependent upon predetermined electrical conditions in the main' machine.

5. In a system of control, the combination with a mainI dynamoelcctric machine, of a controlling device therefor, a switch for effecting certain main-machine connections, an auxiliary dynamo-electric machine for actuating said device, and means actuated by the closure of said switch for rendering the operation of said auxiliary machine dependent upon the main-machine load.

6. In a system of control, the combination ma machinemiomyactuatingw said device,

causeries nafoperativeiposition to its a: controlling device therefor,

nimdynamoelectrc machines-f a v i '.LIdevdethereor, a switchffor @tingen supply-,circuit connection `for the in @,an auxiliary dynamo-electric and said auxiliary-machine ssfsaidswitch is closed. control, the combinacircuit and ai main macion'enrgizi motor 7. In i system of blnfillhr-' Supply y y' tric mwhinafofa controlling. :larice therefor, a .fon-completingthe mnectionfofasaidwmachine across said qireuit, an auxiliaryy dynamo-electric combination machine, of an auxiliary dpamwble'etric machinet'or actuating said deviana lineswitchfand another switch for the. -niain machine, and means ghlent; yupon the am i i m 9. In: a system of control, the with a; main dynamo-electric closure of the line and the opening of` said other switch movement of the controlling for octingl f' device in t e forward direction from its ,nalmoperative position to its otl posiswitches for' eifecting-moveinent otthe conftrolling'device rom-any operative positionV to' the--i-nitial position.4 13. In a system of control, thecombinar. tion with a main dynamorelectric kmachine, of a; controlling Idevice therefor, auxiL iary dynamo-electric machine for actuating said device, a plurality of switches .for effecting certain main-maehineconnections, means dependent upon the. posit-ion of said switches for eiecting movementof the controlling de.-P vice in the forward direction from any op erativelposition to. the initialposition, yand means for preventingmain-machine operation dnring'such movement." l

14. Ina system of control, the' combinationwith a dynamo-electric lmachine andak controlling device -`therefor, of means fresponsive respectively to .ther machine load and to only its own current xunderdiierent voperating conditions of the system for actuating said device.

'15. In a system4 of control, the combination with a dynamo-electric machine and la controlling device therefor, oda switch for effecting certain machinecircuit connections,

means for actuating said device, and means governed by said switch for regulating the operation of said actuating means.

16. In a system of control, .the-combination with a dynamo-electric-ymachine and a controlling device therefor, of a switch for eii'ectin certain machine-circuit connections, means or actuating said device, and means responsive to the closure of. said switch for rendering the energization of said actuating means dependent upon predetermined electrical conditions in said machine. -v f 17. In a system of control, the combination with a dynamo-electricamachin'e anda 105 controllingjdevice. therefor, of a .switch for eiiecting certain machine-circuit connections, means for actuating said device, and means responsive to the closure of said switch for rendering the operation of said actuating means dependent upon the machine load.

18. In a system ofcontrol, the combination with a dynamo-electric machine and a controlling device therefor, of a switch for eiecting certain machine-circuit connections, plural-winding means for actuating said device, and means responsive to the closure of said switch for connecting certain of the windings of said machine and of said pluralwinding means in parallel relation.

19. In a system of control, the combination with a dynamo-electric machine and a controlling device therefor, of a pluralwinding means for actuating said device, and connections whereb the voltages of the windings of said plura -winding means are varied inversely as the machine load increases.

20. In a system of control, the combination with a dynamo-electric machine and a 10. vIn a system of control, the combination'fwith a main dynamelectric machine, of a controllin device therefor, an auxiliary dynamo-e ectric machine for actuating. said device and having an armature and a field winding, and means for varying 'the voltages of said armature and field winding inversely as the main-machine load in- 1 creases.

11. In a system of control, the combination with a main dynamo-electric machine, of a controlling device therefor, an auxilia d nemo-electric machine for actuating [said evice, a switch for electing certain main-circuit connections, and means responf sive to the closure of said switch for decreas- `in the armature voltage and increasing the fie d voltage of said auxiliary machine.

g 1 2. In a system of control. the combination with a main dynamo-electric machine, of a controlling device therefor, an auxiliary dynamo-electric machine for actuating said device, a plurality of switches for effecting certain main-circuit connections, and means dependent upon the position ofvsaid ply sourceoof controlling device therefor, of a plural-v yind' means tor'aetuating said device, a switch for eiecting certain machinefcirc'uit closure of switch for creasing and ecreasi the vo windings of saidV plura -windiig means. v- 21:11 a sysem of control, e combination-with a supply circuit, a dynamo-electric l of a,v switch for completing the connection of said machine said supply circuit, phnal-winding meansV for actuat' saiddevicgandmeansmspoosivetotheclo'- sure of said switch for connecting the maehn'e eld winding in parallel relation to one-of the vindin of said actuating means. 22.` A system `control comprising a suply circuit, a mainmotor, a second motor avnng an armature and a field-magnet winding, and means for second motor to said supply circuit and to said main motor that said fieldmgnet winding of said second motor will be increased andthe current through the rannotare of said second motor will'he decreased, upon' the load upon said main motor bong? increased.

23. A control comprising a supcnargy, a main motor cond to said aupfplyv source, a resistor connected to said'suppl'y source, a second inotol* having an armature and a field-magnet winding, and means .for so connecting said Second 'motor to said resistor and to said across said varies directly'as the load on said main motor and the voltage across said armature varias inversely as the load upon said-main motor. v

' 24. lA system of control comprising a supply circuit, 'a motor having an amature vand i s, and'means responsivefto the actively in` tasas Ofistl' and acontrolling device therefor,

soy connecting said Y the energization ofk `a. lieldmagnst winding, a second' motor having'an armature and yu eldwinding, means vfor electrically counselling, said motors between their respective anniv tures and lieldauagnet windings, and means magnet winding-an auxiliary motor having' afield-magnet-'winding means for connecting` said' field-magnet windings in parallel, and` means comprisin a resistor for main taining a substantial y constant potential across saidauxiliary motor.

26. A systemof` control comprising a sup ply circuit,.a ymain motor, having an armature and a field winding, and a resistor adapted to be cmnected in parallel rahtion across said supply circuit, a secondmotor having an armature and a field-winding connected across one portion of said resister, and means for connecting pointsy in'-V tmnediate the armatures vand eld windings of the respective motors. i

27. A system of'controlaxnprising a mpply circuit, a main motor, having an arma ture and a field winding and aY resistor adapted to be connected in parallel relation across said supply circuit, a second motor having an amature and a field winding connected across one portion of said resistor, means for connecting nts intermediate the armatures and ficlvm windings ofthe respective motors, and means whereby operation of the main motor is the movement of the second motor.

`In testimony whereof, I have hereunto subscribed my name this 27th day of March,

BASCUM o, AUSTIN.

theA controlled by 

